Intrinsic dew-enhancing ability of SiO2/PODS materials

A superhydrophobic polymerized n-octadecylsilane (PODS) surface with a highly ordered lamellar structure was obtained via a one-step solution immersion process. The PODS surface had water contact and sliding angles of 159° and ∼0°, respectively. A hydrophilic/superhydrophobic surface was then obtained by chemically bonding nano-SiO2 onto the PODS surface. This SiO2/PODS layer exhibited dew-enhancing ability, similar to that of the surface of the stenocara beetle. Vapor condensation occurring heterogeneously on the SiO2/PODS surface is proposed to explain the dew-enhancing property, and these hydrophilic/superhydrophobic surfaces may have applications in enhanced heat transfer.